Modified Heterodigital Neurovascular Island Flap for Sensory Reconstruction of Pulp or Volar Soft Tissue Defect of Digits

Analysis of thumb pulp reconstruction based on different local flaps: A systematic review

Background

The reconstruction of the thumb's pulp is challenging when considering that there is no consensus on which local flap will provide better prognosis and less financial impact. The aim of this study was to analyze the outcomes of the most used flaps for the trauma to the volar substance of the thumb, validating the main indications.

Methods

This systematic review adhered to PRISMA guidelines and electronic searches were conducted in multiple databases (MEDLINE/PubMed, Virtual Health Library, Embase and Scopus) with studies published in the last ten years - until April 2022.

Results

The search resulted in the screening of 573 records, and twenty studies were included. Among the flaps analyzed and compared by outcomes and prognostic factors, there are First Dorsal Metacarpal Artery (FDMCA), modified (MFDMCA), Moberg flap, Heterodigital Neurovascular Island, Neurovascular Island Pedicle and Modified Littler.

Conclusion

Through this literature review, we can analyze different flaps widely used in the daily life of hand surgeons. The flaps that were also positive in a global context, but with few criticisms, are the MFDMCA, Moberg Flap, Neurovascular Island pedicle flap and FDMCA. However, it is important for the surgeon to consider different prognostic factors when choosing the flap, since these aspects directly impact the return to daily activities after the procedure.

Comparison of Treatment Methods of Thumb-Tip Defects With Phalangeal Bone Exposure: Modified Heterodigital Neurovascular Island Flap Versus Free Lateral Great Toe Flap

PURPOSE

Modified heterodigital neurovascular island flaps and free lateral great toe flaps are dependable methods for treating thumb-tip defects with phalangeal bone exposure. We retrospectively analyzed and compared the details and results of the two methods.

METHODS

This retrospective study included 25 patients with thumb injuries with phalangeal bone exposure treated between 2018 and 2021. Patients were categorized as per the following surgical methods: (1) modified heterodigital neurovascular island flap (12 patients, finger flap group) and (2) free lateral great toe flap (13 patients, toe flap group). The Michigan Hand Outcome Questionnaire, aesthetic appearance, Vancouver Scar Scale, Cold Intolerance Severity Score, static 2-point discrimination, Semmes-Weinstein monofilament, and range of motion of the metacarpophalangeal joint of the injured thumb were evaluated and compared. In addition, operation time, hospital stay, return-to-work time, and complications were recorded and compared.

RESULTS

In both groups, the defect was successfully repaired, with no cases of complete necrosis. The 2 groups had similar mean scores in static 2-point discrimination, Semmes-Weinstein monofilament, range of motion, and Michigan Hand Outcome Questionnaire scores. The aesthetic appearance, scarring, and cold tolerance of the toe flap group were better than the finger flap group. The operation time, hospital stay, and return-to-work time in the finger flap group were shorter than the toe flap group. The finger flap group had 2 complications-a superficial infection and 1 case of partial flap necrosis. The toe flap group had 3 complications-a superficial infection, 1 case each of partial flap necrosis, and partial skin graft loss.

CONCLUSION

Both treatments can achieve satisfactory results; however, they each have advantages and disadvantages.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Fingertip degloving injury coverage with homodactyle bipedicled dorsal island flap

OBJECTIVES

To investigate the curative effect of repairing digital degloving with flaps from the bilateral dorsal branch of the proper digital artery of the same finger.

MATERIAL AND METHODS

Twenty-three patients with fingertip degloving injury treated with flaps from the bilateral dorsal branch of the proper digital artery of the same finger in our hospital from February 2020 to March 2022 were retrospectively included. Active finger range of motion, cold intolerance, pain on visual analogue scale and patient satisfaction were evaluated.

RESULTS

There were 3 cases of flap blister and 2 of vascular crisis after the operation, all of which healed after symptomatic treatment. All the other flaps and skin grafts survived. Follow-up ranged between 6 and 25 months (mean, 13.8 months). The skin flap was full in shape and soft in texture. Incidence of cold intolerance was low in the palmar flaps and dorsal flaps, and finger range of motion recovered well. The technique relieved pain, and patients were satisfied with the results.

CONCLUSION

Flaps from the bilateral dorsal branch of the proper digital artery of the same finger were effective for repair of fingertip degloving. The technique easy to implement, and can repair large defects; the repaired finger shows good function and appearance.

Comparison of Clinical Outcomes of Heterodigital Neurovascular Island Flap, Reverse Homodigital Neurovascular Island Flap, and Cross-Finger Flap Used for Fingertip Reconstruction

Objective

The fundamentals of fingertip defect reconstructions should be mainly to restore the sensation with contour and identical pulp volume, and texture. To achieve these, various flap techniques were described in which those had their own advantages and disadvantages to restore the fingertip injuries. This study aimed to compare clinical outcomes of three different local flap procedures widely used for the reconstruction of fingertip defects: heterodigital neurovascular island (HeNI) flap, reverse homodigital neurovascular island (rHoNI) flap, and cross-finger (CF) flap.

Methods

Between 2014 and 2019, statistical analysis of 58 patients undergoing reconstruction of fingertip defects of 2-5 digits by HeNI flap (n = 16), rHoNI flap (n = 17), or CF flap (n = 25), was performed retrospectively. All cases were reviewed regarding age, gender, etiology of trauma, duration of follow-up, the extent of the injury with the classification system PNB, Quick Disability of Arm, Shoulder, and Hand score (Q-DASH), cold intolerance symptom severity score (CISS), static 2-point discrimination test, ROM value of phalangeal joints and time to return to work.

Results

The mean age of all patients was 36.9 years with a male-to-female ratio of 5.4:1 and a mean follow-up of 26.72 months. The most common cause was work-related (n = 41). The mean of DASH score, CISS score, static 2-point discrimination, time to return to work, and ROM value of DIP joint did not significantly differ between the study groups. The mean ROM values of PIP and MCP joints of patients for CF flaps applied were significantly lower than HeNI flaps.

Conclusion

The use of HeNI flap for fingertip reconstruction is a reliable one-stage option in terms of improved ROM of finger joints.

The Clinical Effect of Digital Dorsal Fascial Island Flap Combined With Crossfinger Flap for Repairing Distal Degloving Injury and Sensory Reconstruction

Background

To explore the clinical effect of digital dorsal fascial island flap combined with crossfinger flap to repair distal degloving injury and sensory reconstruction.

Methods

A total of 19 patients with distal fingertip degloving injuries treated with digital dorsal fascial island flap combined with crossfinger flap in our hospital from April 2018 to August 2020 were retrospectively included. Semmes–Weinstein (SW) monofilament and static two-point discrimination (S-2PD) tests, active range-of-motion (ROM) of the fingers, cold intolerance, visual analog scale (VAS) score patient complications, and patient satisfaction were evaluated.

Results

Five cases with post-operative flap blisters were treated at the time of dressing changes until successful scab formation. Three cases with post-operative arterial crisis of finger arterial dorsal branch vessel were relieved after suture removal and tension reduction. All other skin flaps and skin grafts survived. Nineteen patients received follow-up between 3 and 26 months (average 14.6 months). The active ROM of metacarpophalangeal (MCP) and interphalangeal (IP) joints of the injured fingers were satisfactory.

Conclusion

The digital dorsal fascial island flap combined with the crossfinger flap for repairing the distal degloving injury of the distal segment of the finger is a good surgical method, which is simple and easy to operate, can repair a large area of soft tissue defect, and obtain a satisfactory effect.

Functional and aesthetic reconstruction of a dorsal digital skin defect with a sensory neurotized DMCA III flap

The dorsal metacarpal artery (DMCA) flap is an elegant way to reconstruct tissue defects. We present a 25-year-old female patient with a dorsal injury on the fourth digit, which was reconstructed with a third webspace DMCA flap which was neurorrhaphied with a branch of the ulnar nerve, to regain sensation.

The Application of Digital Design Combined with 3D Printing Technology in Skin Flap Transplantation for Fingertip Defects during the COVID-19 Epidemic

Objective

We aimed to evaluate the advantages of preoperative digital design of skin flaps to repair fingertip defects during the COVID-19 pandemic. We combined digital design with a 3D-printed model of the affected finger for preoperative communication with fingertip defect patients under observation in a buffer ward.

Methods

From December 2019 to January 2021, we obtained data from 25 cases of 30 fingertip defects in 15 males and 10 females, aged 20-65 years old (mean 35 ± 5 years). All cases were treated by digitally designing preoperative fingertip defect flaps combined with a 3D-printed model. Preoperative 3D Systems Sense scanning was routinely performed, 3-matic 12.0 was used to measure the fingertip defect area ranging from 1.5 cm × 3.5 cm to 2.0 cm × 5.0 cm, and the skin flap was designed. The flap area was 1.6 cm × 3.6 cm to 2.1 cm × 5.1 cm. CURA 15.02.1 was used to set parameters, and the 3D model of the affected finger was printed prior to the operation. Full-thickness skin grafts were taken from donor areas for repair.

Results

No vascular crises occurred in any of the 25 cases, and all flaps survived. The postoperative follow-up occurred over 3-12 months. All patients were evaluated 3 months after operation according to the trial standard of hand function evaluation of the Chinese Hand Surgery Society. The results showed that 20 cases had excellent outcomes (80%), four cases had good outcomes (16%), and one case had a fair outcome (4%). The excellent and good rate was 96%.

Conclusions

During the COVID-19 epidemic, fingertip defects were treated with preoperative digital design of fingertip defect flaps combined with 3D printing. Precision design saves surgery time and improves the success rate of surgery and the survival rates of skin flaps. In addition, 3D model simulations improve preoperative communication efficiency, and the personalized design improves patient satisfaction.

Fingertip defect reconstruction with a modified pivot flap

The pivot flap can treat volar oblique defects of the fingers distal to the distal interphalangeal joint. We present our experience in 11 fingers (11 patients) using this flap, including some modifications that optimize flap harvesting, mobilization, inset, and vascular supply and outcomes. The flaps harvested had an average size of 2.4 × 2.0 cm. The patients were followed for an average of 21 months (range 12 to 36) after surgery. Sensitivity of the flap was evaluated with the Semmes-Weinstein monofilaments test and static two-point discrimination test. Cold intolerance was also evaluated. The pivot flap with the modifications demonstrates a reliable technique for fingertip defect reconstruction. The results, in terms of sensitivity and functional recovery, seem promising.Level of evidence: IV.

Quantification of axonal ingrowth and functional recovery in a myocutaneous flap model in rats with strong clinical implications

The process of reinnervation, an important component of functional restoration after flap transfer, is understudied, making it necessary to carry out a further investigation for delineation of the exact timeline. Seventy-six Sprague-Dawley rats were used as the experimental animals. An anatomic study was first conducted to clarify the pattern of nerve distribution in the dorsal skin of 16 rats. Afterward, a myocutaneous flap was harvested on the right flanks of 40 rats, which were then assigned into seven time points. At each time point, skin samples were harvested and immunofluorescent staining was performed using α-Bungarotoxin, and antibodies against NF-200, p75, α-SMA, and TH. One-way analysis of variance was adopted for comparison of nerve density after surgery. For evaluation of functional return, cutaneous trunci muscle reflex (CTMr) test was performed on 10 additional rats, and the Chi-square test was used for comparison of reflex intensity among six time points after surgery. The outcomes revealed that the cutaneous branches from the intercostal nerves and the dorsothoracic nerve from the brachial plexus could be found entering the dorsal skin, distributed in the skin proper and the panniculus carnosus, respectively. After flap surgery, full spontaneous reinnervation of the skin proper and vessels within the flaps could be achieved at day 180. However, if the stumps of cutaneous branches of the intercostal nerves were damaged, the nerve density in the skin proper underwent a 2/3 decline. The panniculus carnosus in the cranial part had a much better reinnervation than that in the caudal part. The CTMr test showed that the flap could regain most of its sensate and motor activity. Our study shows that strong spontaneous reinnervation could be expected after flap surgery. The pattern of the original nerve distribution in both the recipient and donor sites may have a big impact on the reinnervation of the flap.

Repair of distal thumb degloving injury using combination of reverse dorsoradial flap of the thumb and middle finger proper digital arterial island flap

BACKGROUND

To examine the efficacy of combination of the reverse dorsoradial flap of the thumb and middle finger proper digital arterial island flap for repair of distal thumb degloving injury.

METHODS

Twelve patients with mechanical distal thumb degloving injuries were treated between February 2017 and August 2019. A combination of the reverse dorsoradial flap of the thumb and the middle finger proper digital arterial island flap were used. Semmes-Weinstein (SW) monofilament and static two-point discrimination (S-2PD) tests, active range-of-motion (ROM) of the joints, cold intolerance, visual analog scale (VAS) score patient complications, and patient satisfaction were sequentially evaluated.

RESULTS

Two cases with postoperative flap blisters were treated at time of dressing changes up to successful scab formation. One case with postoperative arterial crisis of finger arterial dorsal branch vessel was successfully released in the pedicle. Ten cases healed by first intention and 2 cases by secondary intention. Twelve patients received follow-up examinations between 3 and 20 months (average 13 months) post-treatment, and all exhibited full, soft flaps with no fingertip pain.

CONCLUSION

The combined use of the reverse dorsoradial flap of the thumb and the middle finger proper digital arterial island flap is a practical and effective approach to surgical repair of distal thumb degloving injuries.

Pedicled flap from the first dorsal branch of the proper palmar digital artery of the fingers: An anatomy study

The pedicled flap from the first dorsal branch of the proper palmar digital artery (FBPPDA) of the fingers is an option for reconstructing digital skin defects. It has the advantage of being innervated by the dorsal branch of the proper palmar digital nerve (DBPPDN) associated with the artery. However, no studies on the anatomical variations of the neurovascular pedicle have been performed yet. The objective of our study was to evaluate the anatomical variations in the neurovascular pedicle, determine its relationships with other anatomical structures, describe the dissection technique for the FBPPDA and explore potential indications. We conducted an anatomical study with eight upper limbs from fresh adult cadavers. Twenty-six fingers (6 index, 6 middle, 8 ring, 8 little) were dissected after intra-arterial silicone injection. We found a pedicle composed of the FBPPDA and the DBPPDN in all fingers. The artery arises an average 19mm from the bifurcation of the common palmar digital artery. The DBPPDN's configuration relative to the FBPPDA varied; in the main variant - found in 58% of cases - the nerve was superficial and proximal position to the artery. After its origin, the pedicle ran on the superficial aspect of the extensor hood along an oblique path from proximal to distal and from palmar to dorsal. Its path ended with its penetration into the skin paddle of the flap just upstream the proximal interphalangeal (PIP) joint. The skin paddle corresponded to the functional skin unit represented by the dorsal surface of the middle phalanx and that of the PIP joint. Its average length was 33mm (26-40) and its average width was 21mm (15-30). The arc of rotation was sufficient to reach homodigital and heterodigital cutaneous defects. Based on our findings, this flap is a reliable and reproducible option for finger skin defects. The size of its paddle and its innervation make it an interesting alternative to conventional flaps.

Reconstruction of Finger Pulp Defects With an Innervated Distally-Based Neurovascular Flap

PURPOSE

Finger pulp resurfacing is a challenging reconstructive problem. This article introduces sensory reconstruction of finger pulp defects using an innervated distally-based neurovascular flap raised from the dorsum of the thumb.

METHODS

From May 2015 to May 2017, the innervated distally-based neurovascular flap was used in 36 patients. The mean age at surgery was 37 years (range, 18-61 years). All patients were assessed using the total active motion (TAM) scoring system of the American Society for Surgery of the Hand. The sensitivity of the flap was tested using static 2-point discrimination.

RESULTS

Full flap survival was achieved in 35 cases. Partial necrosis at the distal margin of the flap was observed in 1 case. At the final follow-up (mean, 20 months; range, 18-23 months), the mean TAM of the thumb was 206° (range, 188°-238°), including 8 excellent and 28 good results. The mean TAM of fingers was 266° (range, 251°-282°), including 4 excellent and 32 good results. The mean value of static 2-point discrimination was 5 mm (range, 4-7 mm) in the flap, including 31 excellent and 5 good results.

CONCLUSIONS

The innervated distally-based neurovascular flap raised from the dorsum of the thumb is a reliable alternative for sensory reconstruction of finger pulp defects.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.